This invention is directed to a locking cam-type coupling for rapidly coupling two pipe sections together. A spring-biased lock pin is provided for each cam lever arm that has a positive locking action when the cam lever arm is moved to the closed position. Each cam lever arm is grooved to allow the spring-biased lock pin to contact the cam lever arm and control its position. The lock pin has two different diameters, one for locking the fitting to the complementary part of the pipe coupling to couple the pipe sections together, and a second, open position so the pipe sections can be released and decoupled.
1. Discussion of Related Art
U.S. Pat. No. 4,222,593 issued Sep. 16, 1980 to Lauffenburger relates to a coupling having a safety locking device. A male and a female coupling member are adapted to be coupled together and held in place by a pair of pivotal coupling arms.
The arms are mounted on the female half of the coupling, and each includes a cam portion which is engageable in a groove in the male coupling member. The pivotal coupling arms compress a sealing member between the male and female couplings when they are closed against the female coupling.
Each coupling arm is further provided with a safety locking device mounted on the female coupling member, which comprises a reciprocally mounted locking pin, a spring for biasing the locking pin to a locking position overlying the coupling lever, and a manual lever member which engages the locking pin, and which pivots to retract the locking pin to a lock-release position. Locking and unlocking requires manual operation of the locking member. It is possible to operate the locking pin independently of the coupling arm, and if the locking pin is in the locked position when the coupling arm is not closed, the locking pin must be manually operated before the coupling arm can be closed.
U.S. Pat. No. 5,042,849 issued Aug. 27, 1991 to Kersting shows a coupling for a flexible hose which incorporates a pair of locking arms similar to those shown in the Lauffenburger patent. However, positive locking means for the cam locking arms is not shown.
U.S. Pat. No. 5,042,850 issued Aug. 27, 1991 to Culler, shows a safety latch cam and groove-type quick disconnect coupling which allows the pressurized fluid line to bleed down to a safer pressure before being fully disconnected. The cam-locking arms do not appear to have locking pins.
Although the Lauffenburger patent shows a safety locking device for coupling lever arms, the locking device comprises a complex mechanism which includes a lock pin 56 operated by a spring-biased latching lever 16. The lock pin 56 has an abutment shoulder to limit its forward motion. It is necessary for the lock pin 56 to disengage the latching lever 16 completely so that latching lever 16 can be pivoted to its coupling disconnect position.